Interior vehicle trim elements may be formed as a supporting substrate with an overlying skin layer in which its outer surface is visible within the vehicle interior when installed. Sometimes, the skin and substrate are separated by a foam layer, as is known. Such a trim element, for example designed to cover a dashboard, a door panel, or another panel of a vehicle, for example a motor vehicle, makes it possible to define the aesthetics of the passenger cabin of the vehicle. Consequently, it is generally desirable to give the skin of the trim element a particular appearance so as to make the passenger cabin pleasant to see and touch.
To that end, it is for example known to impart a particular texture to the outer surface of the skin, such as a predefined graining. Graining consists of forming a network of asperities on the outer surface of the skin following a particular pattern defining the outer appearance of the trim element. The graining may be more or less fine as a function of the dimensions of the asperities, but there is a minimal fineness beyond which the graining is no longer seen. To give the trim element a pleasant feel, it is known to position the skin under a substrate layer having a certain flexibility, such as a foam layer.
In order to still further improve the aesthetics of the trim element, a provision may be made for adding a decorative element attached on the outer surface of the skin, in a particular area thereof. This decorative element is for example a part made from a plastic, wooden or other material or a pattern formed by one or more inks or of any other suitable nature. It is provided to adhere this decorative element on the outer surface of the skin after or during the assembly thereof with the substrate layer, for example using a heat-activated glue or thermocompression or an ink transfer between a substrate film and the outer surface of the skin or other.
However, the adhesion of such a decorative element is done on the apex of the disparities forming the graining of the outer surface, which causes poor adhesion between the decorative element and the skin and may cause premature wear of the decorative element, or even its detachment from the skin, damaging the appearance of the trim element. In fact, the decorative element does not continuously adhere to the outer surface of the skin, and the adhesion points are not sufficient to ensure robust fastening of the decorative element. Furthermore, it is possible for the step for fastening the decorative element to damage the foam layer positioned under the skin.